Improvement in means for attaching saw-handles



ii 255L25 R. CROSBY. v I Means of Attaching Saw-Handles.

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N.PETERS. PHOTO'LITHOGRAFHER. WASHINGTON, D10,

UNITED STATES PATENT OFFICE.

RENSLOW CROSBY, OF BOSTON, MASSACHUSETTS.

IMPROVEMENT IN MEANS FOR ATTACHING SAW-HANDLES.

Specification forming part of Letters Patent No. 206,540, dated July 30, 1878; application filed June 26, 1 878.

clamps, connected with and movable over the clamp-screws.

In the Spring and Robinson patent the screws are rigidly afiixed to the bow, pass loosely through unthreaded clamps, and the said clamps are held to the how by superposed nuts. In others the screws pass loosely through clamps, and their ends fit into threaded holes in the bow; but both of these inventions differ from mine in that the screws and the clamps of my saw are entirely separable from the bow, do not wear out any part of the bow, and are renewable when worn out, without necessarily involving any repairs to the bow itself, which is not the case in the others.

I have ascertained by experiment, if the thread of the screw is made to engage only the thread of a clamp, that the bow never becomes worn so as no longer to be serviceable, and that a screw and clamp, when worn so as to be unserviceable, may be readily replaced by a new screw and clamp, one bow serving to outwear a number of screws and clamps. This matter of saving in cost of bows, they being frequently of cast-steel, is a very considerable item.

Figure 1 represents, in side elevation, a bowsaw-frame constructed in accordance with my invention, and Fig. 2 a sectional detail of the end of the bow and clamp on the line as w.

The bow a, provided with a suitable handie, a, has the flattened portions 1) I), provided with holes for the free passage through such portions of the clamp screws 0, which are threaded to engage only the screw-threaded interior portion of the clamps d, only one of which is shown in the drawing, it being understood, however, that each portion 1) and screw and clamp at each end of the bow are alike.

A steadyingpin, e, retains the clamp from turning aside upon the screw when the latter is being turned to pinch the end of the sawblade between the bow and clamp. The thread of the screw not engaging a thread of the bow, the latter is not worn by such screw and rendered useless. The clamp and screw may, when worn, be discarded and new ones added to the bow.

I claim- 1. The bow-frameprovided with holes for the reception of the clamp screws, which permit them to move therein freely, combined with the clamp-screws and screw-threaded clamps fitted to the ends of the clamp-screws, to operate as and for the purpose described.

2. The bow, screwthreaded clamp d, and

steadying-pin, combined with a clamp-screwv adapted to extend freely and loosely through a hole in the bow, and fit the screw-threads of the clamp, to operate substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

RENSLOW CROSBY.

Witnesses:

G. W. GREGORY, N. E. WHITNEY. 

